Stretching clamp



May 23, 1933. wq E DE LAND 1,910,003

STRETCHING CLAMP Filed Sept. 5, 1930 2 SheetS-Shee l May 23, i933. w. E; DE LAND STRETCHING CLAMP Filed Sept. 5, 1930 2 Sheets-Sheet 2 Patented May 23, 1933 UiNrrEn `STATES PATE-nr orFicEf ,f

WALTER n DE LAND, or MILWAUKEE, WIscONl'sIn,4 AseIeNoa To Darme sysirzaivis; INC., or CHICAGO, ILLINOIsA CORPORATION or IIfIazivoIs4 a srRETcIIINe CLAMP Application leil September 5, 1930. Seria-1 No'. 479,889.

,This vinvention relates to *stretching` clamps. While Athe clamp `is particularly` adapted for the stretching of leather `'hides and 4other material, itis nevertheless to be distinctly yunderstood that the invention is not to 4be limited to a leather stretching clamp, but is applicable to any use Where" it is desired to stretch sheet material.

In developing this invention,the stretching of leather Will 'be discussed in detail asv one of the `many applications of the invention, but as stated, it is V notte be understood in lany ysense as limiting the invention to the stretchingo leather.

In :stretching leather -it is ltheusual practice to take the leather-after tanning and While it is Wet and stretch it. In the usualpractice it is lfrequently the case that the leather is stretched and tacked on frames, or

else the leather is engaged by clamps which are grippedin the handof the operator and pulled outwardly and :thereafter hooked into a perforated frame. It Will be readily. Lseen that the stretching is an uncertain quantity, depending' greatly upon the skill ot the op-` era-tor, and also it is apparent that the maxi* mum stretching cannot be determined by this method. Further, it frequently happens that when the operators hand slips from anyA cause whatsoever, that hishand is in contact with the perforated metal frame or the, means to Which it is`r desired toy attach.

the clamp. The'consequence of this is that the oper-atorfs hand isfcut or injured by 5 scraping it across the trame. 4In addition to this detect, the operators hand is in an awk-Ward position and projects below the clamp, thus greatly hindering him in attaching the clamp in place.

Further than this, it is apparent that kwith thisA uncertain method of stretching, that they grain is frequently injured as an attempt to place considerable tension upon the leather,

frequently results in either too much tension` or too little tension, thereby altering` the appearance ot the grain land spoiling theleather or hide for certain uses.

This invention is designed `to overcome the detects noted above, and the objects Ofthis invention are to -providella clamp ,which *not only gripsthe leather, but also stretches the leather a predetermined amount. The

clamp `in yactual practice secures an 1addi-vv tional stretching of the leather Which has not heretofore been possible. When" it isfcjonsidered that slight increase all Vthe Way' around a side or hideresults in a material increase in Vthe areaof the leather or hide, and When it is appreciated that .the leather issold by ,the square foot,it `is at once apparent `that even Y a. small :gain-comsv pletely around the sidenor `-hide Will resul-t in a material: increase in the number of square feet available for sale. yThis inven-ly tion. accomplishes the above Voutlined obj ects- Without injuring the leather in any Way, as it secures an additional :andpredetermined amount of stretching.V Y

Further objects of this invention-areto.

the deviceto vthe ,perforated sheet metalvr support. A further provide a stretching clamp Which allows the leatherto be stretched to the desired extent by the operator and which thereafter'provides a pre-determined amount of additional stretching which cannot `be yexceeded and which does not damage the grain ofV ,they leather, but which protects the grain of thevk leather, as this predetermined amount of; stretchingis uniformly uapplied thro'ug'h'outV the entirefside or hide. Y v

Further objects are to provide a stretch ing clamp Which is of very .simple construction, which has no Yfragile or Ieasily damaged.

parts, which .is cheapto make, which may be Jformed from stampingsif fdesired, me

which is ,easyfto operate..4 a

Ob-ieot of this* invention to"` In certain forms of the invention, a further object is to provide a stretching clamp having the characteristics above noted,

lwhich automatically opens and closes the clamping jaw when the main lever or member is manipulated so that only one operation is required of the operator instead of two. That is to say, the manipulation of the main member not only stretches the leather a pre-determined amount, but also controls the gripping of the leather by the clamp, thereby securing this double function.

It is to be distinctly understood that the term leather is used in `this description and 'in the appended claims to designate any sheet material which it is desired to stretch and is merely used to avoid needless repetition.A -j

lllmbodiments of 'the invention'are shown in the accompanying drawings in which Fig. 1 is a longitudinal sectional view of a leather-stretching device embodying my invention, the device being shown applied to a portion of aleather-supporting frame; Fig. 2, afsimilar sectional view showing the improved device after the clamp which engages the leather has been shifted or telescoped within the mounting which is hooked onto the leather-supporting frame; Fig. 3, aplanview of the improved device, the stretched leather vbeing shown brokenly; Fig. 4, a longitudinal sectionalview showing 35, a modification of the invention; and Fig; 5,

a longitudinal vsection showing another modification. v

Referring to the drawings, it kwill be seen that the usual supporting means has been shown asa frame"(i1) provided with perforated metal strips (2) carried thereby.

Theclamp comprises a body portion (3),y

which'is formed of sheet metal and is channel shaped, although obviously other shapes could'V be employe The channel shaped body portion, however, is preferred as it permitsthe use of the body portion as a guide for aslide (4), also formed vof sheet metal. The .slide (4) is a movable member, as will be seen from Figuresl, 2and 3, and is adapted to slide inwardly or outwardly within the channel shaped body portion. It is operated'by means of a toggle link mechani'sm consisting of a sheet metal channel 55, shaped manipulating lever (5), which isv pivoted, as indicated at (6), portion. This lever is l provided with a. looped grip (7), so that the operators linger may be inserted therein if so desired. However, in the initial operation, the lever projects vertically upwardly, as shown in Figure 1, and thevhand of the operator grips around the upwardly projecting lever.

`Thel lever (5) vis connected to the slide by meansof vone or more links `(8) as shown. The pivots (6) do not extend completely within the body across the body portion, as may be seen from Figure 3, and thus permit the rocking of the lever (5) downwardly, as will hereinafter be described, into a position to carry the rear pivot point (9) of the links (8) past dead center, as shown in FigureV 2, to thus lock the slide (4) in its retracted position.

The forward ends of the llinks (8)1are pivoted, as indicated at' ('10) to the slide (4)'.

yIt is preferable to turn a pair of ears (11) over from the body portion (3) so as to effectively hold the slide (4) against upward motion. l.

The slide (4) is provided with any sort of clamp adapted to engage the leather or other sheet material (12). For. example, the slide may be provided with an upturned: lip (13) ywhich cooperates with a down-r turned lip or recessed member (14)'of an upper clamping jaw (15),.the slide forming the lower clamping jaw. `This upper clamping jaw (15) is operated by means of a small hand lever (16). It is to be distinctly understood at this point that other types of clamps maybe employed. 2

It "s also preferable to form the body.. portion (3) with a downwardly vand for wardly projecting hook (17), which is; adapted to enter any one of the apertures (18) in the support, as shown lin Figures 1 and 2. .f

In operating the device, the lever (5)'.is mQved to a vertical position, as shown in: Figure 1, and the edge of the leather (12) is gripped, 'as indicated in such figure. Thereafter, the operator grasps thel upwardly projecting lever and draws the entire mechanism backwardly and hooks the hookl (17) through the appropriate aperture (18) in the support. Durinothis operation the operators hand Vis tected, even if the clamp should slip, as the bodyportion of the stretching clamp is between his hand and the support,v and consequently no tearing of the operators hand can result as was frequently heretofore the CaSe.

After the stretching clamp has beenl locked to the support, theoperator gives the leather an additional predetermined stretch by rocking the lever (5) downwardly, thereby drawing thel leather rearl determined amount.

wardly a fixed and pre j In actual practice it has been found that this predetermined additional stretch givenf the leather does not injure the grain-and materially increases the total area of the leather. In view of the fact that the leather is sold by the square foot, it is apparentV that an additional saving is secured by this,V

apparatus.

It is tobe noted particularly` that lno judgment is required of the' operator in securingv this additional stretch, as the ad-r iilly profstl ditionalvv stretch is pre'-determinedlY fandffcannot be exceeded even by a'carel'essroperator: Further, it will befnotedthlatthe operatorsr hand is-fullyl "protected- "at ald `times and there is yno `danger of `cutting or't'earinghis hand when thisapparatus is used'.

In v.the extensible. stretching-devies, or.

unit, described, the* body 3. fconstitutes, fa

hook-equipped: mounting; the-slide d and parts carried thereby :constitute albedily# shiftable `clamp -lhaving forwardly :presented gripper-jaws; and the `lever and ilinlrs S constitute a manually operated jc'lampsretracting Adevice byA means oi which reafr' ward shittingfof the olfampimay :be eieeted after the clamp has ygripped theI leather` and' the mounting, :or basesfr'ame, B1 been hooked onto the foraminous member '2L of theileather-supporting frame 1.

In effect, lthe clamp i'svadapted to bertelescoped within: the mounting 'in the-collapsed: condition of ythe leather-stretching device.. It'may `be remarked lthat while the urnA proved* leather-stretching.deviee isvin tle extended condition, it may be manipulated: to apply to the leatheranuintial :handsp'ull which.=may bev ocsu'ch intensity as the par'- ticular portion fof the lea-ther may require, and', thereafter, Lay leverfpullY of pre-determined amplitude. v Consequently, a -greater' stretch than has heretofore been possible with a devi-cey of `this general type niaiyfbe safely applied to the mathemati-such peints as require it. A5150, leaserof .release-@isf an important feature of the .improved devine, since the lever may bethrown over to relieve the pull pri'orito` disengaging ithe hoolu from the'leether-supportingl trameb Referring lto Figure 4, itwililfbecseen that.

:4d the same idea is carried eut'inrthissormwof:

the invention. Inv this form ot the invern tion, a body portion '(19). ifs provided which is constructed in a manmer'quite similarto that' previously described. Itfcarriesthe` slide which'v is: equipped' with'. an iup turned lip or j-aw 21). i

The slide-.(201) isiconneote'd to:` thelieverv (2 2) 4by one-orniorelinlrs (123'). as shown.. i' Thev movable jaw (24l)-iisformed-integrally with loosely pivote'd to.v the yslide (201),.. r1llhe member 25) is provided withzzanrlupwardly pressed recessed. portion (126)V whiche houses.

a small compression .spring (27)... Theufpf wardly pressedportion (26:): engages fat' cam; surface yformed integrally with the body portion (19). Thiscani; consists oiflaniupturned iiat portion (28).

dotted line position, as shown in Figure 4, the movable jaw is raised upwardly, as shown in dotted line, due to the sliding of the upward projection (26) upon the portion (27) of the cam. This automatically the member (25), which is.

portion. :(277)V and: a horiaentalA or opensthe clamp and permits `the `insertion of the-edge 'oithe leather. :When-theflever '(22)` fis initially `moved rearwardly to i-.ts full line position, 'the'.projecti'on. ('26) lslides downwardly beneath the horizontal= portion o'fvthe" cai-mf, and 'thus' lautomatically closes fthe jaws. `flhereafter the operator vgripping. the'upwardly vprojecting lever (22) can tbe emplUyd;l In this-form of v.theV invention the body' portion (130)r carries vthe slide (81) in thefsame manneras that previously'rdescribed. The sli'de isl provided With an 'upturn'ed lip` (32), Which-cooperates with 'the dovvnturnediv lipof the upper' clamping' jaw' .(34) small lever opensfand: olosesLthe-jawsas y'it' is rocked about `its pivotblpoifnt (36)'.y The lever (35?) is urged into the position shown in.` Figurer?) by-mea'ns 'of a springI "(37).` However, it is adapted to' be rocked inthe Contrary direc? tion., ithat isfin a counter-'clockwise `direction as viewed in Figure 5, by 'means of the link (38) (pivoted 1to1 .the slide operating link.' (39 )1. It isto bernotedfthat the slide-operating link is provided with a slot (401) within Whiehthe forward! in (41). andeonneeting the `to` the slid (38);wis also slotted, as indicatedat: (42).

In th'egposition :of 'the `parts .shown in. Fig; ure 5 tliejja'ws 'are just :about to. bereleased.

f The operating'leverf'mot' showin) is `inits verticali position',` as; has been shown Vini Y iull lines ini Figure "4. A slight ladditional .tor-` ward rocking of this operatinglever' causes the link. (39)'- to/move forwardly and to force-"the connested'V flink .(38)l ior'wardly, thus 'engaging'the lpin' (.43)A carried-:at the.'

upper end of the locking lever (3:5).. This eois located. vThe' link' rocks the lever (35)15in la counterLolockwlise l directienr, and raises the upper jawy as the lever' (35:){1engage's beneaththe-tongue (4.4) of tliemember (3:4)- .i l

lObviously when 'the main" or operating lever isfrin'xitially: roeked-v a.".sli'ghty distance rearwardly, ther 'jaws aref again closed.` 5

through V'the action ofthe spring (.37)r and thelo'ckiug levers (35. Furtliemmotion of the )main lever .retraots-y the .slide and:

provides the additionalrstretch "heretofore:-v

d'escribedx i It is to ibesdistinctly lunderstood.thatnthe means for automatically opening and` closing the jaws may bevaried,v and that the particular forms chosen'forvillustration are merely illustrative of the generall principle.

Any suitable means may be employed for limiting the forward motiony of the slides in the different forms ofthe invention.. For example, in Figure-the slide (3l) is pro-v vided with shoulders (45) whichengage the inturned lips (46) of the body portion (30).

In the form shown in Figures, 1 and4, the links (8) and (23)7 mayrespectively. contact with the portions(l1)y and (28,). lAlsouin these two forms, the bottom forward corner ofthe lever (5)V or'Y (22) respectively may engage the bottom ofthe body. portion, and may thus limit the=fo`rward-n1otion of the slide.l

It will be .seen that ahn'ovel form. of stretching clamp has been provided which is of extremely vsimple construction, which is eminently practical, which` is reliable'inoperation, andvwhich is very easyto` operate.

It will be seen further that `the novelform of stretching clamp provides ja pre-determined additional stretch, protects thehand ofthe operator, and doesnot destroy.y orin any way injure the grain of the leather.

It will be seen furtherthat the kdevicevmay be formed of Sheet'metal stampings ifso de-- sired, and that it mayulbe made with the utmost cheapness'. .5; j v

Although the invention has been described in considerable detail, itl is to be understood that such description is intended as illustrative rather than limiting','-and the ap-l pendedclaims are to be construed as broadly as permissible, in view ofjthe. prior. art.

Iclaimz- 1 y 1. An extensible stretchingdevice unit of the character set forth, comprising: Ya mounting equippedwith ;means for engaging a support; a bodily-shiftableclamp on said mounting, havinga forwardly .pre` sented pair of gripperfjaws and manual' actuating means connecting :said mounting said `stretching-device. f

2.*A deviceV as specified finclaimfl, in

which the rear end ofsaid mounting has its and clamp, operative to extend fand'y collapse,

" 4- operation ofshifting said clamp-0n said lower sideequipped with a hook'adaptedto.

engage said support. l. 3. A device as specified in .4. A device as specified in-.claim 1,-ini

which said clamp is slidable within said mounting andhas its gripper-jaws vprofjected some distance in radvance of theforf ward end of thevmounting when the device is in extended condition.

5. A device as specified in claim-1l', .in

`claim 1,-.inx .which said actuating means-is equipped with a finger-piece adapted yto bethrown.

which .said actuating :means kcomprisesfa hand-,lever having pivotal v.connection with said, mounting and'v having link-connection with the body-portion of lsaid clamp.

6.Ay ,device as specified in claim l, in which said Y actuating ymeans comprises a hand-lever equipped :with a linger-piece and armspivotally connected near :their free ends with. side, walls with which said mounting isprovided, and comprises, also, links disposed-.betweenthe planesof said arms and pivotally connected .atoneend with saidgarms and-:attheotheiaend with the body-portion of saidv clamp. f i v I Aidevice asspecilieduin claim 1,-fin which said. mounting'fcomprises a member of Usha`ped cross-.section having an .open front end. and ytlnebottom fwall of said mounting is v,equipped with a dependingl forwardly extending hook; and in which said actuating; means comprises fai lever pivotally-connectedwith the'side .wallsfof saidmounting Yand links connecting `'said lever with the side -Vwalls cfa-the bodyf of ,said clamp..fy i. .f y 8. A- device as specified in claimv 1;, in which .said mounting. comprises 'a' member of yU-shape cross-sectionv having an open frontV end andthe rbottom wall-of said mounting is equipped*with fadepending forwardly extending hook; in which said actuating meanscomprises a-lever pivotally connected with lthe-'side 7walls l=of said mountingand links connecting said leverA with theeside walls off the body .v of said clamp; and inv which one'of' said gripperjaws isl a` movable lever-actuated member.

9. An extensible stretching-device unit lof the `fcharacter; yset pforth,iv comprising: a

mounting equipped with means foruengaging al support.; a bodily-shiftable clmp slidably carried by -said; mounting having a forwardly presented `pair of gripper-jaws,

one of which is movablegfactuating means connecting said. mount1ng.-and clamp, op;-

erative to extend and "collapse said stretch.k

ing-deviceyand'means for automatically actuating the .movable gripper-j aw during the mounting. 1

:10. An :extensible stretching-'device 'unit' of the character set'VfOrth, comprising: a mounting equipped with/means for engaglngA a support; iai bodilyfshiftable clamp on 'y saidmounting having a forwardly presentgripper` jaws; and .actuating WALTERQDE LAND. 

